Strong nestable paper food tray

ABSTRACT

Paper food trays that are able to be compactly stacked together and that contain side walls and a bottom with gusset corners formed by overlapping gusset panels and paperboard blanks for forming the trays are described herein. These nestable food trays are stronger than nestable food trays that do not contain a gusset corner. Further, they are particularly useful to carry and hold foods that include a sauce or other liquid. The food trays are generally temporarily leak proof, such as for at least about 5 minutes, preferably for at least about 10 minutes, more preferably for at least about 15 minutes, after the food is placed in the tray.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. provisional application No. 62/155,340, filed Apr. 30, 2015, the disclosure of which is incorporated by reference herein in its entirety.

FIELD OF THE INVENTION

The invention is generally directed to food packaging, particularly nestable paper trays.

BACKGROUND OF THE INVENTION

A variety of disposable paper trays for food exist. Nestable containers fit inside each other, and allow a large number of containers to fit inside each other, taking up less space for storage and/or shipment. Currently nestable food trays are generally formed from a blank that contains a flap attached to one side wall panel which can be glued to an adjacent side wall panel. However, these trays leak if liquid, such as a sauce or soup, is placed in the tray.

Therefore, there is a need for improved nestable paper trays which do not leak when liquids are placed in the tray.

SUMMARY OF THE INVENTION

Paper food trays having side walls and a bottom with gusset corners formed by overlapping gusset panels and paperboard blanks for forming the trays are described herein. When assembled, the side walls are generally at an angle that is greater than 90° from the bottom of the tray. These food trays are able to be stacked one on top of the other, where the bottom of one tray is typically in contact with or very close to the bottom of another tray. These trays are particularly useful to carry and hold foods that include a sauce or other liquid. The food trays are generally temporarily leak proof; such as for at least about 5 minutes, preferably for at least about 10 minutes, more preferably for at least about 15 minutes, after the food is placed in the tray.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1E are different views of an exemplary paper food tray. FIG. 1A is a top perspective view. FIG. 1B is a side perspective view. FIG. 1C is a bottom view. FIG. 1D is a side view of a short side of the tray, the opposite side being a mirror image thereof. FIG. 1E is a side view of the long side of the tray, the opposite side being a mirror image thereof.

FIG. 2 is an exemplary paperboard blank that can be used to form the tray depicted in FIGS. 1A-1E.

FIG. 3 is another example, paperboard blank that can be used to form a paper food tray with gusset corners.

FIG. 4 is another exemplary paperboard blank that can be used to form a paper food tray with gusset corners.

DETAILED DESCRIPTION OF THE INVENTION I. Assembled Food Tray

The paperboards described herein can be assembled to form a food tray with four sidewalk and a bottom, where each sidewall is attached to an adjacent side wall via a gusset corner. Preferably the trays do not contain a flange at the upper portion of the tray.

These food trays are nestable, such that they are able to be compactly stored, and are stronger than currently available nestable food trays that do not contain a gusset corner. Further, the food trays described herein are particularly useful to carry and hold foods that include a sauce or other liquid, and prevent leakage of the fluid out of the tray.

The gusset corners are formed by folding the gusset panels at a suitable angle to allow the side walls to align at an angle greater than 90°, typically at an angle ranging from 100°-120°, relative to the bottom of the tray. In preferred embodiments, the walls are located at an angle of about 110° from the bottom of the tray.

As shown in FIGS. 1A-1E, when assembled, the food tray contains four side walls, where two are shorter 21 a and 21 b and two are longer 20 a and 20 b and a rectangular bottom 18. Optionally, the bottom is in the shape of a square and all four side walls have substantially the same dimensions.

Each side wall attaches to an adjacent side wall via a gusset corner 30. As shown in FIG. 1A and 1B, preferably the gusset corners are adhered to the shorter sides 21 a and 21 b. However, one of ordinary skill in the art will appreciate that the blank can be modified to accommodate adhering the gusset corners to the longer sides or to a combination of the shorter and longer sides (e.g. one gusset corner adhering to each side).

The side walls may have substantially the same height when assembled. Alternatively, a set of two parallel side walls may be slightly taller than the other set of two parallel side walls. As shown in FIGS. 1B and 1E, the set of parallel side walls 21 a and 21 b, Which correspond with the shorter side of the bottom rectangle, are slightly taller than the other set of parallel side walls, 20 a and 20 b.

The gusset corners are attached to a side wall using a suitable adhesive, such as a food grade glue.

II. Nested Food Trays

A plurality of food trays described herein that have the same dimensions can be nested, i.e. stacked on top of each other such that the bottom of one food tray touches, or is very close to the bottom of the adjacent food tray. In this manner, a large number of food trays can fit in a relatively small space, for ease of storage and/or shipping.

In contrast to the trays described herein, food trays that are configured with a side wall that is substantially straight, e.g. at an angle of approximately 90° relative to the bottom of the tray, take up a larger volume of space when stacked. Further when food trays having the same dimensions and with substantially perpendicular side walls relative to the bottom of the tray are stacked on top of each other, the bottom of one food tray is not able to touch the bottom of the adjacent food tray, rather the bottom of one food tray lies substantially at or near the top of the food tray that is beneath it.

III. Paperboard Blank

A paperboard blank is used to form the single use, disposable paper tray described herein.

Different types of food grade paperboard may be used to form the blank and ultimately the tray. The paperboard is optionally ovenable paperboard suitable for use in conventional and microwave ovens. The paperboard may be coated with a suitable food grade material to reduce leakage, such as a polyester resin film. Optionally, the side of the paperboard blank that forms the inside surface of the resulting tray is coated with a liquid impervious polymer film.

The paperboard blank contains a plurality of score lines that define a central polygonal bottom panel, which forms the bottom of the tray, when it is assembled. The score lines on the bottom panel form a plurality of bottom edges, which also serve as the bottom edge of an adjacent side wall-forming panel. The side wall-forming panels extend outward from the bottom panel and are generally trapezoid-shaped. The bottom edges can be folded to assemble the side wails such that they are angled away from the bottom at an angle greater than 90°.

In preferred embodiments, the bottom panel is in the shape of a rectangle. Optionally, in some embodiments, the bottom panel is in the shape of a square. However, the bottom may be in the shape of other polygons.

Each side wall-forming panel is attached to an adjacent side wall-forming panel via a pair of gusset panels. In a given pair of gusset panels, each gusset panel is attached to the other gusset panel in the pair via a first fold line, and each gusset panel in the pair is attached to the adjacent side wall-forming panel via a second fold line. The second fold line is at a suitable angle for forming a tray with side walls that extend from the bottom at an angle of greater than 90°, typically at an angle ranging from 100 ° to 120 °.

In one embodiment, depicted in FIG. 2, the paperboard blank 10 contains a rectangular bottom panel 18 defined by fold lines 24 a, 24 b, 24 e, and 24 d, which are located on each side of the rectangle. Each fold line also forms the inner edge of respective side wall-forming panels, 20 a and 20 b for the long side panels, and 21 a and 21 b for the two short side panels. Each side wall-forming panel is generally trapezoidal in form. The outer edges of each side wall-forming panel 32 a, 32 b, 32 c, and 32 d, also correspond with the top of the paper tray.

The gussets 30 a, 30 b, 30 c, and 30 d in the tray are formed from overlapping gusset panels 40 a and 40 b connected by a fold line 42 that is substantially in the center between the two gusset panels. Side fold lines 44 and 46 connect the respective gusset panels to the side walls with sealing portions of the gusset panels extending the full depth of the side walls,

Preferably the outer panel 40 a side fold line 44 is located approximately 115° relative to the bottom panel fold line 24 a. Similarly, the fold line 42 between the gusset panels is preferably located approximately 135° relative to the bottom panel fold line 24 a. Additionally, the outer inner panel side fold line 46 is preferably located approximately 158° relative to the bottom panel fold line 24 a.

The outer edges of the gusset panels for the blank depicted in FIG. 2 are defined by a substantially straight line 45, which connects on one side to the outer edge 32 a of a first side panel 32 a, and at the other end connects to an angled edge 43, which connects to a corresponding angled edge 41 of a second adjacent side panel 21 b. The gusset angled edge 43 connects with side panel angled edge 41 at an angle of approximately 144°. Other angles that allow the gusset panels to align and adhere to the side panels are also envisioned.

In one embodiment, the paperboard blank contains a gusset panel with a cut-out portion. The cut-out portion is located in the inner gusset panel that attaches to the side wall. By including a cut-out, adhesive is also placed on a portion, typically the upper portion of the outer gusset, thereby directly sealing the outer gusset to the side wall as well.

For example, as shown in FIG. 3, the paperboard blank 100 contains a rectangular bottom panel 180 defined by fold lines 240 a, 240 b, 240 c, and 240 d, which are located on each side of the rectangle. Each fold line also forms the inner edge of respective side forming panels, 200 a and 200 b for the long side panels, and 210 a and 210 b for the two short side panels. Each side panel is generally trapezoidal in form. The outer edges of each side panel 320 a, 320 b, 320 c, and 320 d, also correspond with the top of the paper tray.

The gussets 30 a, 30 b, 30 c, and 30 d in the tray are formed from overlapping gusset panels 400 and 410, which are connected by a fold line 420 that is substantially in the center between the two gusset panels. Side fold lines 440 and 460 connect the respective gusset panels (400 and 410, respectively) to the adjacent side walls (200 b, 210 a, respectively) with sealing portions of the gusset panels extending the full depth of the side walls.

One gusset panel 400 in each pair of gusset panels optionally includes a cut-out portion 430, which allows bonding of the outer gusset panel 410 against the outer surface of the corresponding side wall strengthening the corner of the tray and allowing the outer gusset panel to seal directly to the sidewall, instead of sealing to the inner gusset portion.

The cut out portion 430 is defined by outer edges 415 and 414. As shown in FIG. 3, the outer edges 415 and 414 define the cut-out portion in the shape of a V. Alternatively, the cut-out portion 430 can be located on the corresponding gusset panel 410, such as shown in FIG. 4. One of ordinary skill in the art would understand that other geometries are suitable for the cut-out portion, to allow the outer gusset to attach directly to the outside surface of the side wall.

The outer edges of the gusset panels for the blank depicted in FIGS. 3 and 4 are defined by a substantially straight line 413, which connects on one side to an outer edge 414 of the cut-out portion, and at the other end connects o an angled edge 412, which connects to a corresponding angled edge 411 of an adjacent side panel 210 b. The angled edge is configured to allow the gusset panels to align when the tray is assembled.

Unless defined otherwise, all technical terms used herein have the same meanings as commonly understood by one of skill in the art to which the disclosed invention belongs.

Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the following claims. 

We claim:
 1. A paper food tray comprising side walls and a bottom, wherein each side wall is connected to the adjacent side wall with a gusset corner, wherein each gusset corner adheres to one of the side walls.
 2. The tray of claim 1, wherein the tray does not contain a flange.
 3. The tray of claim 1, wherein each gusset corner is formed from a pair of gusset panels connected by a first fold line defining one side of each gusset panel, and wherein a second side of each gusset panel is defined by a second fold line, wherein each of the second fold lines is located between one of the gusset panels and the side wall that is adjacent to the gusset panel.
 4. The tray of claim 3, wherein one of the gusset panels in each pair of gusset panels comprises a cut-out portion and the other gusset panel in each pair does not contain a cut-out portion.
 5. The tray of claim 1, wherein the bottom is in the shape of a rectangle.
 6. The tray of claim 1, wherein each of the side walls is located at an angle of greater than 90° with respect to the bottom.
 7. The tray of claim 6, wherein the angle ranges from about 100° to about 120°.
 8. A plurality of food trays as defined in claim 1, wherein all of the food trays have the same size and shape, and wherein each of the plurality of food trays is able to be stacked within another of the food trays, such that the bottom of one tray is next to the bottom of the adjacent tray.
 9. A paperboard blank for forming the food tray of claim
 1. 10. The paperboard blank of claim 9, comprising a plurality of score lines defining a central polygonal bottom panel having a plurality of bottom edges, wherein each bottom edge is foldably connected to one edge of a radially outwardly extending trapezoidal side wall-forming panel, wherein each side wall-forming panel is attached to an adjacent side wall-forming panel by a pair of gusset panels, wherein each gusset panel in the pair is attached to the other gusset panel in the pair via a first fold line, and wherein each gusset panel in the pair is attached to the adjacent side wall-forming panel via a second fold line.
 11. The paperboard blank of claim 10, wherein one gusset panel in a pair of gusset panels comprises a cut-out portion and the other gusset panel does not contain a cut-out portion.
 12. The paperboard blank of claim 10, wherein each gusset panel terminates in a straight edge that is connected to an angled edge, wherein each side wall terminates in a straight edge, and wherein each angled edge is attached to the straight edge of the adjacent side wall.
 13. The paperboard blank of claim 10, wherein the central polygonal bottom panel is in the shape of a rectangle. 